JP4201366B2 - Color TV door phone device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color television door phone slave device and a color television door phone device having a white LED that emits white light.
[0002]
[Prior art]
Conventionally, a television door phone device is disclosed in Japanese Patent Application Laid-Open No. 61-43889 (conventional example 1). This television door phone device has a monochrome image, and has employed a light emitting diode (LED) that emits infrared light as illumination for a subject, particularly when natural light is low in illuminance such as at night or in the evening. This utilizes the fact that a CCD, which is an image sensor, also has sensitivity in the near-infrared region, so that an object illuminated with near-infrared light can be imaged. And since a visitor who is a subject illuminated with near infrared rays does not notice that it is illuminated, it can take an image without giving the visitor an uncomfortable feeling, and the LED is inexpensive and has a long life. is there. In this type of TV door phone device, the illuminance of the infrared light from the LED is always constant, so if the illuminance of the subject changes depending on the surrounding environment, adjust it with the shutter control function of the video camera. As a result, an image with proper exposure was obtained.
[0003]
Further, a television door phone device in which video is colored is disclosed in Japanese Patent Laid-Open No. 1-243794 (conventional example 2). In this color TV door phone device, when shooting a subject by irradiating the subject with infrared illumination in an environment such as at night when it is difficult to obtain subject illumination, the color camera outputs a color video signal with an unnatural color. In order to solve the problems such as the low S / N ratio and poor color reproducibility when the subject color illuminance is lower than the white color video signal in the night color video signal, the environment where the subject illuminance is low Below, the unsightly color of the subject is automatically cut and switched to black and white video.
[0004]
Further, a color television door phone device that can always obtain a color image even at night without switching the color to a black and white image in an environment where the illuminance of the subject is reduced as in the above-described conventional example 2 is disclosed in Japanese Patent Laid-Open No. 4-269090. It is disclosed in the gazette (conventional example 3). This color TV door phone device is arranged near a parent device installed indoors, a child device that is electrically connected to the parent device via a signal line and disposed at the entrance, and the like. And an illuminating device provided.
[0005]
As described above, the signal line connecting the master unit and the slave unit is a pair of parallel lines (pair line) as disclosed in, for example, Japanese Patent Application Laid-Open No. 62-257287 (conventional example 4). Yes. A color video signal and an audio signal composed of a color signal and a luminance signal are transmitted on the pair of parallel lines.
[0006]
Furthermore, in Japanese Patent Application Laid-Open No. 61-167292 (Conventional Example 5), the distinction between color and black-and-white images is not clear, but the illumination unit provided in the slave unit when the subject illumination is low at night. A television door phone device configured to turn on illumination is disclosed.
[0007]
[Problems to be solved by the invention]
However, as in Conventional Example 2, when a video door phone device is to be colorized using, for example, a color CCD, the near red light emitted from the light emitting diode when the subject illumination is low such as at night. When the subject is illuminated with external light, the image becomes an unnatural color of, for example, a single blue color. In addition, when the subject is mixed with ambient light such as natural light in addition to near-infrared light, the image projected on the color monitor described above is further unnatural and difficult to see.
[0008]
Further, as in the conventional example 3, in the color television door phone device in which the illumination device is arranged in the vicinity of the slave unit so that a color image can be obtained even at night, the illumination device is separate from the slave unit, and the entrance, etc. There are problems in workability such as the necessity to construct both of them and the power supply wiring of the lighting device.
[0009]
Furthermore, as disclosed in Conventional Example 5, since the power is supplied separately even if the illumination unit is arranged integrally with the slave unit, the illumination unit is similar to Conventional Example 3. Power supply wiring must be further performed, and workability becomes a problem.
[0010]
The present invention uses a small light source that emits white light that can be arranged in the main body of the child so as to illuminate the subject, and suppresses the enlargement of the child, and provides a clear color image even at night. It is an object of the present invention to provide a color television doorphone slave device and a color television doorphone device that can be obtained.
[0011]
[Means for Solving the Problems]
The invention of claim 1 includes a slave unit body, a solid-state image sensor that is photoelectrically converted to output a color video signal, an automatic gain adjustment circuit, and improves manual exposure operation sensitivity. Manual exposure control means configured to set to increase gain when operated to the side, video signal processing means for performing signal processing on the color video signal output from the solid-state image sensor and outputting a video signal, An audio signal processing means for outputting sound as an audio signal disposed in the slave unit main body, a white LED disposed in the slave unit main body for illuminating a subject with white light, and a white LED disposed in front of the irradiation direction. A color television doorphone slave unit including a light diffusing unit provided; a color monitor for displaying a video signal output from the video signal processing unit; and an audio signal output from the audio signal processing unit Characterized in that it comprises a; and color television doorphone master station having a force to the speaker; a color television-equipped intercom slave and a pair parallel lines electrically connecting the base unit.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a perspective view of a color television door phone apparatus showing an embodiment of the present invention. The TV door phone device is composed of a slave unit 1 installed on the outdoor side and a master unit 2 installed on the indoor side, and both are electrically connected by a cable (a pair of parallel lines) 3.
[0017]
The slave unit 1 includes a color CCD 1b, which is a solid-state image pickup device, a button switch 1c of a doorbell, a microphone 1d that collects a visitor's voice, a speaker 1e that outputs the voice of the responder, and a surrounding environment that is dark. In this case, it has a white LED 1f which is a small light source that emits visible light (white) that illuminates a visitor. A light diffusing means 1g is disposed in front of the irradiation direction of the LED 1f, and the light emitted from the light source is diffused. Therefore, particularly in the case of a directional LED or the like, the subject can be illuminated uniformly. In addition, it is possible to make it difficult for a visitor who is a subject to feel dazzling.
[0018]
Here, the outline of the white LED manufactured by Nichia Corporation used in the present embodiment will be described below. This white LED has the same basic structure as a normal InGaN-based blue LED, but the phosphor surface is thinly coated on the chip surface of the light source. The blue light emitted from the chip is incident on the phosphor, and after being repeatedly absorbed and scattered in the phosphor, is emitted to the outside. At this time, the blue light absorbed by the phosphor acts as an excitation source and emits yellow fluorescence. And this yellow light and blue light mix and it looks white. The characteristics of this white LED are a light intensity of 3 cd, an efficiency of 5.0 lm / W, and a color temperature of 8000 K at a current of 20 mA and an ambient temperature of 25 ° C.
[0019]
FIG. 5 is a spectral distribution diagram of the white LED. According to this, light is emitted in the visible light wavelength range of about 380 nm to 800 nm, and in particular has spectral characteristics having a gentle emission peak around 450 nm showing blue light and around 550 nm showing yellow light.
[0020]
FIG. 6 is a spectral distribution diagram of an incandescent light bulb (white lamp manufactured by Toshiba Lighting & Technology Corp.). According to this, light is emitted in the visible light wavelength region and the infrared wavelength region of about 400 nm to 2000 nm, and most of the energy is emitted in the infrared wavelength region.
[0021]
FIG. 7 is a spectral distribution diagram of a fluorescent lamp (Mellow 5N manufactured by Toshiba Lighting & Technology Corp.). According to this, light is emitted in a visible light wavelength range of about 400 nm to 720 nm, and in particular, it has spectral characteristics having emission peaks in red light, green light, blue light and the like.
[0022]
As described above, incandescent light bulbs that are mostly in the infrared wavelength region and have low energy in the visible light wavelength region are difficult to illuminate the subject sufficiently and do not provide sufficient color. In addition, in a fluorescent lamp having spectral characteristics having a plurality of emission peaks, the hue of a color image is likely to be influenced by any one of the emission peaks. In this case, it is necessary to adjust with a fluorescent lamp or a video signal processing circuit. Further, the fluorescent lamp requires a special lighting circuit and may be large and expensive.
[0023]
Therefore, in order to obtain a clear color image, a continuous spectrum such as natural light is most preferable, light is emitted in a visible light wavelength region of about 380 nm to 800 nm, and a spectral characteristic having a gentle emission peak. The white LED having the above is easily adopted in such a case.
[0024]
A CdS sensor for detecting the illuminance of visible light is also provided, and the LED 1f is turned on or off according to the output of the sensor, as will be described later.
[0025]
The master unit 2 outputs a handset 2b in which a color monitor 2a that displays a visitor's video, a speaker that outputs a visitor's voice, and a microphone that collects the visitor's voice are integrally attached, and a ringing tone. A speaker is provided.
[0026]
During a period of low illuminance, such as at night, the LED 1f is lit to illuminate the visitor. The color CCD 1b images a visitor illuminated with visible light emitted from the LED 1f. Note that a call with a visitor can be performed without any trouble by the speaker 1e and the microphone 1d of the slave unit 1 and the handset 2b of the master unit 2. If the visitor presses the button switch 1c, a ringing tone is generated from the speaker of the main unit 2.
[0027]
According to the present embodiment, when the illumination is low such as at night, the visitor is illuminated and imaged with visible light from the LED 1f, so that the screen is very easy to see and the appearance of the visitor is easily checked. be able to. Furthermore, since an inexpensive and long-life light source such as the LED 1f can be used, the maintenance of the apparatus can be facilitated and the running cost can be kept low.
[0028]
FIG. 2 is a block diagram of a television door phone device showing an embodiment of the present invention. In the figure, reference numeral B denotes an image pickup unit that picks up a visitor A that is a subject and obtains a color video signal B1, and is collected by the lens B2 that collects the reflected light of the visitor A and the lens B2. The CCD 1b is photoelectrically converted into a color video signal B1.
[0029]
Reference numeral C denotes video signal processing means for driving the CCD 1b and performing various processes on the color video signal B1 obtained from the CCD 1b to generate and output a video signal C1 composed of a luminance signal and a color signal. Symbol D is a CdS sensor that detects the illuminance of visible light. A symbol E is a determination unit that determines whether or not the illuminance level of the surrounding environment detected by the CdS sensor D is lower than a set value. Reference numeral 1 f is an LED that emits visible light for illuminating the visitor A, and the LED lighting control means F controls the lighting of the LED 1 f based on the lighting signal from the determination unit E. Also, the audio signal processing means G outputs the audio collected by the microphone 1d disposed in the slave unit main body 1a as the audio signal G1.
[0030]
FIG. 3 is a graph showing the spectral characteristics of the CdS sensor. According to this graph, a CdS sensor having a sensitivity in the visible light region having a wavelength of 400 nm to 700 nm is used but has no sensitivity to infrared rays having a wavelength of 700 nm or more.
[0031]
FIG. 4 is a characteristic diagram showing the relationship between the resistance value of the CdS sensor and the illuminance. The CdS sensor D has a characteristic that its resistance value decreases as the illuminance increases. The numbers in the figure indicate the type of CdS sensor D.
[0032]
Further, in the present embodiment, the exposure control means is improved so that the following problems can be solved. In other words, in order to ensure the tone reproducibility of the color monitor that is required for all ambient environments from low to high illuminance, conventionally, only automatic exposure and manual exposure control has been performed. Even if the highlight portion is present in the color monitor screen, the automatic gain adjustment circuit lowers the gain, resulting in a dark screen setting as a whole.
[0033]
On the other hand, if the entire screen is dark even if the sensitivity reduction operation is performed, there is a problem that the automatic gain adjustment circuit improves the sensitivity and the highlight portion is crushed white.
[0034]
Therefore, in the manual exposure control means H as shown in Figure 2, to set the manual exposure operation set when operating in the increased sensitivity side to the gain increase, the gain reduction when operating the manual exposure operation decreased sensitivity side configuration It was.
[0035]
In other words, automatic exposure control circuit, manual exposure control circuit, these control circuits variably control the electronic shutter speed to set the exposure, and when CCD starts up, it starts with automatic exposure, and then manual exposure by manual exposure operation after that It is equipped with an automatic gain adjustment circuit for the video signal obtained by the exposure control, and can control the operation unsuitable for the automatic gain adjustment circuit. Can be generated.
[0036]
Furthermore, in order to obtain gradation reproducibility under low illuminance, conventionally, the gamma value was set low, so that under high illuminance, the white gradation becomes clogged and the highlight part skips. There was an inconvenience.
[0037]
Therefore, a CCD camera equipped with an automatic exposure function and a gamma value variable function is provided, and when a sufficient video signal level cannot be obtained under low illumination, the gamma value is set to the lowest value and the black side is set as before. The gradation reproducibility can be secured. On the other hand, when the amount of light is sufficiently higher than in the maximum exposure state, the linearity of the high level part of the video signal is improved by setting the gamma value to a relatively larger value than under low illuminance. It is possible to prevent the occurrence of crushing and obtain a good video signal without black crushing and white crushing from low illuminance to high illuminance.
[0038]
【The invention's effect】
According to the first aspect of the present invention, since the white LED that emits white light that can be arranged in the main body of the child so as to illuminate the subject is used, an increase in size of the color TV door phone slave is suppressed. It can be easily arranged inside the cordless handset, and a clear color image can be obtained even at night. In addition, since the light emitted from the light source is diffused, it is possible to uniformly illuminate the subject, and it is possible to make the subject, for example, a visitor, less likely to feel glare. In addition, the exposure control by manual exposure can restrict unintentional operation of the automatic gain adjustment circuit, and can generate a video signal having the brightness desired by the operator.
[Brief description of the drawings]
FIG. 1 is a perspective view of a color television door phone device according to an embodiment of the present invention.
FIG. 2 is a block diagram of a color television door phone device showing an embodiment of the present invention.
FIG. 3 is a graph showing spectral characteristics of a CdS sensor.
FIG. 4 is a characteristic diagram showing a relationship between a resistance value of a CdS sensor and illuminance.
FIG. 5 is a spectral distribution diagram of a white LED.
FIG. 6 is a spectral distribution diagram of an incandescent bulb (white lamp manufactured by Toshiba Lighting & Technology Corp.).
FIG. 7 is a spectral distribution diagram of a fluorescent lamp (Mellow 5N manufactured by Toshiba Lighting & Technology Corp.).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Color TV door phone cordless handset 1a ... cordless handset main body 1b ... Solid-state image sensor 1g ... Light diffusion means 1f ... White LED
2 ... Color TV door phone main unit 3 ... Cable C ... Video signal processing means G ... Audio signal processing means

Claims (1)

This unit has a slave unit, a solid-state image sensor that is photoelectrically converted and outputs a color video signal, and an automatic gain adjustment circuit. Manual exposure control means configured to be set to increase, video signal processing means for performing video signal processing on the color video signal output from the solid-state imaging device and outputting a video signal, and disposed in the slave unit body Audio signal processing means for outputting sound as an audio signal, a white LED disposed in the main body and illuminating the subject with white light, and a light diffusing means disposed in front of the irradiation direction of the white LED A color TV doorphone handset equipped with;
A color TV door phone main unit having a color monitor for displaying the video signal output from the video signal processing means and a speaker for outputting the audio signal output from the audio signal processing means;
A pair of parallel lines for electrically connecting the color TV door phone slave unit and the master unit;
A color television door phone device comprising:

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